The present invention relates generally to missiles and more specifically the invention pertains to a missile airframe protective door assembly which covers an attitude control system (ACS) engine during missile launch, and which is jettisoned when the ACS engine is fired.
A missile's attitude refers to the missile's inflight position with respect to its inclinations with regards to a specific frame of reference. This frame of reference is often the axes of the missile with respect to the earth's surface.
Endoatmospheric missiles can make use of tail fin stabilization systems, but exoatmospheric missiles often use gimbaled engines in mounts as part of an attitude control system. These engines operate as Vernier engines that adjust the attitude of a missile while a main engine provides most of the missile's thrust.
The current practice with a number of existing missile systems, is to fly the missile with no covering over the ACS engine. The disadvantage of this practice is that the ACS engine is susceptible to damage during both storage and launch operations. More specifically, the launch of a missile from a land-based launch tube can subject the ACS engine to heating from the exhaust of the main engine, and severe pebble damage in a pebble impact environment.
The task of providing a protective door to cover missile attitude control system engines during storage and launch is alleviated, to some extent, by the system's disclosed in the following U.S. patents; the disclosures of which are incorporated herein by reference:
U.S. Pat. No. 4,324,167 issued to Piesik;
U.S. Pat. No. 4,321,225 issued to Jelinek; and
U.S. Pat. No. 4,031,806 issued to Stark et al.
The Piesik '167 patent discloses a rear cover for rocket launch tubes providing a seal between the tube and the rear of the rocket. The Jelinek '225 patent relates to access door seals against a convex surface surrounding an opening in a missile casing. The Stark et al '806 patent relates generally to an internal umbilical connector for missiles. This patent discloses that doors are usually provided to close over the missile umbilical connector access in an effort to provide a substantially smooth aerodynamic surface over the missile umbilical connector access during flight of the missile.
While the above-cited references are instructive, a need remains to provide a means for protecting ACS engines during missile storage and launch. The present invention is intended to satisfy that need.